1. Field of the Disclosure
The present disclosure relates to an apparatus and method for driving a liquid crystal display (LCD) device, and more particularly to an apparatus and method for driving a liquid crystal display (LCD) device so as to prevent ripple noise from being generated.
2. Discussion of the Related Art
Thin-and-light flat panel displays (FPDs) have been widely used throughout the world. Specifically, a liquid crystal display (LCD) device has a low operation voltage, so that it only consumes a small amount of power consumption and can be easily carried by a user. As a result, the LCD device is available for a variety of application fields, for example, computers, monitors, spacecrafts, airplanes, etc.
Generally, the LCD device does not emit light by itself, such that another light generated from an additional light source is incident to the LCD device, resulting in the formation of an image. This light source is driven by an inverter.
In this case, the inverter converts a low DC voltage to a pulse width modulation (PWM) signal having a predetermined frequency. This PWM signal is converted into a high-frequency light source voltage capable of driving the light source using a transformer.
FIG. 1 is a block diagram illustrating a conventional apparatus for driving a liquid crystal display (LCD) device.
Referring to FIG. 1, the conventional apparatus for driving the LCD device includes a liquid crystal display (LCD) panel 1 including matrix-type pixel areas formed by orthogonal arrangement between data lines (D) and gate lines (G), a driving circuit 2 for providing the LCD panel 1 with a driving signal and a data signal, and a backlight 8 for providing the LCD panel 1 with a constant light source.
In this case, the driving circuit 2 includes a gate driver 1a, a data driver 1b, a timing controller 3, a power-supply unit 4, and an inverter 9. The gate driver 1a transmits a gate driving pulse to each gate line of the LCD panel 1. The data driver 1b transmits the data signal to each data line of the LCD panel 1. The timing controller 3 receives not only video data (R,G,B) but also control signals (DTEN) (e.g., vertical and horizontal synchronous signals (Vsync and Hsync), and a clock signal (DCLK)) from the driving system 7 of the LCD panel 1. The timing controller 3 formats each display data and the clock and control signals at a timing point where each data driver 1b and each gate driver 1a of the LCD panel 1 can appropriately reproduce data on the screen. The power-supply unit 4 provides individual components of the LCD panel 1 with a necessary voltage. The inverter 9 drives the backlight 8.
Operations of the conventional apparatus for driving the LCD device will hereinafter be described. In more detail, the timing controller 3 receives display data (R,G,B) and control signals (DTEN) (e.g., the vertical and horizontal synchronous signals (Vsync and Hsync) and the clock signal (DCLK)) from the driving system 7 of the LCD panel 1, provides each display data and the clock and control signals at a timing point where each data driver 1b and each gate driver 1a of the LCD panel 1 can appropriately reproduce data on the screen. The gate driver 1a transmits a gate driving pulse to each gate line of the LCD panel 1. The data driver 1b is synchronized with the gate driving pulse such that it outputs the data signal to each data line of the LCD panel 1, resulting in the display of input video signals.
In this case, the backlight 8 may generate ripple noise among video noise signals caused by interference between the output voltage frequency and the horizontal synchronous signal (Hsync) of the inverter 9.